Attempts to create vaccines for some diseases – including malaria, which infects up to 500 million people annually – have failed because patients receiving the experimental inoculations didn't gain immunological memory. That's the ability to produce the right type of antibodies for long periods of time.

“We really don't understand enough about how the immune system works to (design vaccines) in a rational, engineered way,” said Crotty, 35.

He has devoted much of his young career to exploring immunology.

Crotty earned undergraduate degrees in biology and writing from the Massachusetts Institute of Technology, then a doctorate in biochemistry and molecular biology from the University of California San Francisco. He did postdoctoral work at Emory University before joining the allergy and immunology institute in 2003.

The findings published yesterday involve experiments conducted over four years on mice, which have a widely understood genome and an immune system that resembles the one in people.

Crotty's group in La Jolla inserted the Bcl6 gene – the “on” switch – into the mice. They also inserted the Blimp-1 gene, the “off” switch, to shut down the production of antibodies, and removed Blimp-1 genes to restart production.

At Yale, researchers demonstrated another method for halting antibody production by removing the Bcl16 gene from white blood cells.

This alternate approach could prove useful in treating autoimmune diseases, which cause inflammation and painful joints by turning the body's immune system against its own healthy cells.